Now walk_page_range() can walk kernel page tables, we can switch the
arm64 ptdump code over to using it, simplifying the code.

Signed-off-by: Steven Price <steven.pr...@arm.com>
---
 arch/arm64/mm/dump.c | 117 ++++++++++++++++++++++---------------------
 1 file changed, 59 insertions(+), 58 deletions(-)

diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c
index 14fe23cd5932..ea20c1213498 100644
--- a/arch/arm64/mm/dump.c
+++ b/arch/arm64/mm/dump.c
@@ -72,7 +72,7 @@ struct pg_state {
        struct seq_file *seq;
        const struct addr_marker *marker;
        unsigned long start_address;
-       unsigned level;
+       int level;
        u64 current_prot;
        bool check_wx;
        unsigned long wx_pages;
@@ -234,11 +234,14 @@ static void note_prot_wx(struct pg_state *st, unsigned 
long addr)
        st->wx_pages += (addr - st->start_address) / PAGE_SIZE;
 }
 
-static void note_page(struct pg_state *st, unsigned long addr, unsigned level,
+static void note_page(struct pg_state *st, unsigned long addr, int level,
                                u64 val)
 {
        static const char units[] = "KMGTPE";
-       u64 prot = val & pg_level[level].mask;
+       u64 prot = 0;
+
+       if (level >= 0)
+               prot = val & pg_level[level].mask;
 
        if (!st->level) {
                st->level = level;
@@ -286,73 +289,71 @@ static void note_page(struct pg_state *st, unsigned long 
addr, unsigned level,
 
 }
 
-static void walk_pte(struct pg_state *st, pmd_t *pmdp, unsigned long start,
-                    unsigned long end)
+static int pud_entry(pud_t *pud, unsigned long addr,
+               unsigned long next, struct mm_walk *walk)
 {
-       unsigned long addr = start;
-       pte_t *ptep = pte_offset_kernel(pmdp, start);
+       struct pg_state *st = walk->private;
+       pud_t val = READ_ONCE(*pud);
+
+       if (pud_table(val))
+               return 0;
+
+       note_page(st, addr, 2, pud_val(val));
 
-       do {
-               note_page(st, addr, 4, READ_ONCE(pte_val(*ptep)));
-       } while (ptep++, addr += PAGE_SIZE, addr != end);
+       return 0;
 }
 
-static void walk_pmd(struct pg_state *st, pud_t *pudp, unsigned long start,
-                    unsigned long end)
+static int pmd_entry(pmd_t *pmd, unsigned long addr,
+               unsigned long next, struct mm_walk *walk)
 {
-       unsigned long next, addr = start;
-       pmd_t *pmdp = pmd_offset(pudp, start);
-
-       do {
-               pmd_t pmd = READ_ONCE(*pmdp);
-               next = pmd_addr_end(addr, end);
-
-               if (pmd_none(pmd) || pmd_sect(pmd)) {
-                       note_page(st, addr, 3, pmd_val(pmd));
-               } else {
-                       BUG_ON(pmd_bad(pmd));
-                       walk_pte(st, pmdp, addr, next);
-               }
-       } while (pmdp++, addr = next, addr != end);
+       struct pg_state *st = walk->private;
+       pmd_t val = READ_ONCE(*pmd);
+
+       if (pmd_table(val))
+               return 0;
+
+       note_page(st, addr, 3, pmd_val(val));
+
+       return 0;
 }
 
-static void walk_pud(struct pg_state *st, pgd_t *pgdp, unsigned long start,
-                    unsigned long end)
+static int pte_entry(pte_t *pte, unsigned long addr,
+               unsigned long next, struct mm_walk *walk)
 {
-       unsigned long next, addr = start;
-       pud_t *pudp = pud_offset(pgdp, start);
-
-       do {
-               pud_t pud = READ_ONCE(*pudp);
-               next = pud_addr_end(addr, end);
-
-               if (pud_none(pud) || pud_sect(pud)) {
-                       note_page(st, addr, 2, pud_val(pud));
-               } else {
-                       BUG_ON(pud_bad(pud));
-                       walk_pmd(st, pudp, addr, next);
-               }
-       } while (pudp++, addr = next, addr != end);
+       struct pg_state *st = walk->private;
+       pte_t val = READ_ONCE(*pte);
+
+       note_page(st, addr, 4, pte_val(val));
+
+       return 0;
+}
+
+static int pte_hole(unsigned long addr, unsigned long next,
+               struct mm_walk *walk)
+{
+       struct pg_state *st = walk->private;
+
+       note_page(st, addr, -1, 0);
+
+       return 0;
 }
 
 static void walk_pgd(struct pg_state *st, struct mm_struct *mm,
-                    unsigned long start)
+               unsigned long start)
 {
-       unsigned long end = (start < TASK_SIZE_64) ? TASK_SIZE_64 : 0;
-       unsigned long next, addr = start;
-       pgd_t *pgdp = pgd_offset(mm, start);
-
-       do {
-               pgd_t pgd = READ_ONCE(*pgdp);
-               next = pgd_addr_end(addr, end);
-
-               if (pgd_none(pgd)) {
-                       note_page(st, addr, 1, pgd_val(pgd));
-               } else {
-                       BUG_ON(pgd_bad(pgd));
-                       walk_pud(st, pgdp, addr, next);
-               }
-       } while (pgdp++, addr = next, addr != end);
+       struct mm_walk walk = {
+               .mm = mm,
+               .private = st,
+               .pud_entry = pud_entry,
+               .pmd_entry = pmd_entry,
+               .pte_entry = pte_entry,
+               .pte_hole = pte_hole
+       };
+       down_read(&mm->mmap_sem);
+       walk_page_range(start, start | (((unsigned long)PTRS_PER_PGD <<
+                                        PGDIR_SHIFT) - 1),
+                       &walk);
+       up_read(&mm->mmap_sem);
 }
 
 void ptdump_walk_pgd(struct seq_file *m, struct ptdump_info *info)
-- 
2.20.1

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